Setting interface parameters

All network interface drivers, including the loopback interface, require that their host addresses be defined at boot time. This is done with ifconfig(ADMN) commands included in the /etc/tcp shell script. These commands are initially set up based on information you supply during the installation, or during configuration with the Network Configuration Manager.

ifconfig(ADMN) also sets the netmask, broadcast address, and IP address at boot time. You can change any of this information:

• by running the Network Configuration Manager to reconfigure TCP/IP.

• by editing /etc/tcp to include the desired information.

• by running ifconfig and its counterpart, inconfig, from the command line. Refer to ``Configuring TCP/IP tunable parameters'' for more information.

Using the Network Configuration Manager, while intuitive, can take longer than editing the file, especially when you are:

• changing the netmask and broadcast address to make provisions for a subnet.

• changing the broadcast address scheme.

• changing the IP address of the interface.

To edit /etc/tcp:

1. Log onto the system as root.

2. Make a backup of /etc/tcp:
   
   cp /etc/tcp /etc/tcp.00

3. Edit /etc/tcp to include the desired information on lines beginning with ifconfig.

4. Shut the system down and reboot it by using the System Shutdown Manager as described in the SCO OpenServer Handbook. Remember to select Reboot after shutdown when using the manager.

5. After the system reboots and returns to multiuser mode, test TCP/IP by using ping(ADMN) to contact another host.